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1 /*
2  *  linux/fs/hfs/btree.h
3  *
4  * Copyright (C) 2001
5  * Brad Boyer (flar@allandria.com)
6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
7  */
8 
9 #include "hfs_fs.h"
10 
11 typedef int (*btree_keycmp)(const btree_key *, const btree_key *);
12 
13 #define NODE_HASH_SIZE  256
14 
15 /* B-tree mutex nested subclasses */
16 enum hfs_btree_mutex_classes {
17 	CATALOG_BTREE_MUTEX,
18 	EXTENTS_BTREE_MUTEX,
19 	ATTR_BTREE_MUTEX,
20 };
21 
22 /* A HFS BTree held in memory */
23 struct hfs_btree {
24 	struct super_block *sb;
25 	struct inode *inode;
26 	btree_keycmp keycmp;
27 
28 	u32 cnid;
29 	u32 root;
30 	u32 leaf_count;
31 	u32 leaf_head;
32 	u32 leaf_tail;
33 	u32 node_count;
34 	u32 free_nodes;
35 	u32 attributes;
36 
37 	unsigned int node_size;
38 	unsigned int node_size_shift;
39 	unsigned int max_key_len;
40 	unsigned int depth;
41 
42 	//unsigned int map1_size, map_size;
43 	struct mutex tree_lock;
44 
45 	unsigned int pages_per_bnode;
46 	spinlock_t hash_lock;
47 	struct hfs_bnode *node_hash[NODE_HASH_SIZE];
48 	int node_hash_cnt;
49 };
50 
51 /* A HFS BTree node in memory */
52 struct hfs_bnode {
53 	struct hfs_btree *tree;
54 
55 	u32 prev;
56 	u32 this;
57 	u32 next;
58 	u32 parent;
59 
60 	u16 num_recs;
61 	u8 type;
62 	u8 height;
63 
64 	struct hfs_bnode *next_hash;
65 	unsigned long flags;
66 	wait_queue_head_t lock_wq;
67 	atomic_t refcnt;
68 	unsigned int page_offset;
69 	struct page *page[0];
70 };
71 
72 #define HFS_BNODE_ERROR		0
73 #define HFS_BNODE_NEW		1
74 #define HFS_BNODE_DELETED	2
75 
76 struct hfs_find_data {
77 	btree_key *key;
78 	btree_key *search_key;
79 	struct hfs_btree *tree;
80 	struct hfs_bnode *bnode;
81 	int record;
82 	int keyoffset, keylength;
83 	int entryoffset, entrylength;
84 };
85 
86 
87 /* btree.c */
88 extern struct hfs_btree *hfs_btree_open(struct super_block *, u32, btree_keycmp);
89 extern void hfs_btree_close(struct hfs_btree *);
90 extern void hfs_btree_write(struct hfs_btree *);
91 extern int hfs_bmap_reserve(struct hfs_btree *, int);
92 extern struct hfs_bnode * hfs_bmap_alloc(struct hfs_btree *);
93 extern void hfs_bmap_free(struct hfs_bnode *node);
94 
95 /* bnode.c */
96 extern void hfs_bnode_read(struct hfs_bnode *, void *, int, int);
97 extern u16 hfs_bnode_read_u16(struct hfs_bnode *, int);
98 extern u8 hfs_bnode_read_u8(struct hfs_bnode *, int);
99 extern void hfs_bnode_read_key(struct hfs_bnode *, void *, int);
100 extern void hfs_bnode_write(struct hfs_bnode *, void *, int, int);
101 extern void hfs_bnode_write_u16(struct hfs_bnode *, int, u16);
102 extern void hfs_bnode_write_u8(struct hfs_bnode *, int, u8);
103 extern void hfs_bnode_clear(struct hfs_bnode *, int, int);
104 extern void hfs_bnode_copy(struct hfs_bnode *, int,
105 			   struct hfs_bnode *, int, int);
106 extern void hfs_bnode_move(struct hfs_bnode *, int, int, int);
107 extern void hfs_bnode_dump(struct hfs_bnode *);
108 extern void hfs_bnode_unlink(struct hfs_bnode *);
109 extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *, u32);
110 extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *, u32);
111 extern void hfs_bnode_unhash(struct hfs_bnode *);
112 extern void hfs_bnode_free(struct hfs_bnode *);
113 extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *, u32);
114 extern void hfs_bnode_get(struct hfs_bnode *);
115 extern void hfs_bnode_put(struct hfs_bnode *);
116 
117 /* brec.c */
118 extern u16 hfs_brec_lenoff(struct hfs_bnode *, u16, u16 *);
119 extern u16 hfs_brec_keylen(struct hfs_bnode *, u16);
120 extern int hfs_brec_insert(struct hfs_find_data *, void *, int);
121 extern int hfs_brec_remove(struct hfs_find_data *);
122 
123 /* bfind.c */
124 extern int hfs_find_init(struct hfs_btree *, struct hfs_find_data *);
125 extern void hfs_find_exit(struct hfs_find_data *);
126 extern int __hfs_brec_find(struct hfs_bnode *, struct hfs_find_data *);
127 extern int hfs_brec_find(struct hfs_find_data *);
128 extern int hfs_brec_read(struct hfs_find_data *, void *, int);
129 extern int hfs_brec_goto(struct hfs_find_data *, int);
130 
131 
132 struct hfs_bnode_desc {
133 	__be32 next;		/* (V) Number of the next node at this level */
134 	__be32 prev;		/* (V) Number of the prev node at this level */
135 	u8 type;		/* (F) The type of node */
136 	u8 height;		/* (F) The level of this node (leaves=1) */
137 	__be16 num_recs;	/* (V) The number of records in this node */
138 	u16 reserved;
139 } __packed;
140 
141 #define HFS_NODE_INDEX	0x00	/* An internal (index) node */
142 #define HFS_NODE_HEADER	0x01	/* The tree header node (node 0) */
143 #define HFS_NODE_MAP	0x02	/* Holds part of the bitmap of used nodes */
144 #define HFS_NODE_LEAF	0xFF	/* A leaf (ndNHeight==1) node */
145 
146 struct hfs_btree_header_rec {
147 	__be16 depth;		/* (V) The number of levels in this B-tree */
148 	__be32 root;		/* (V) The node number of the root node */
149 	__be32 leaf_count;	/* (V) The number of leaf records */
150 	__be32 leaf_head;	/* (V) The number of the first leaf node */
151 	__be32 leaf_tail;	/* (V) The number of the last leaf node */
152 	__be16 node_size;	/* (F) The number of bytes in a node (=512) */
153 	__be16 max_key_len;	/* (F) The length of a key in an index node */
154 	__be32 node_count;	/* (V) The total number of nodes */
155 	__be32 free_nodes;	/* (V) The number of unused nodes */
156 	u16 reserved1;
157 	__be32 clump_size;	/* (F) clump size. not usually used. */
158 	u8 btree_type;		/* (F) BTree type */
159 	u8 reserved2;
160 	__be32 attributes;	/* (F) attributes */
161 	u32 reserved3[16];
162 } __packed;
163 
164 #define BTREE_ATTR_BADCLOSE	0x00000001	/* b-tree not closed properly. not
165 						   used by hfsplus. */
166 #define HFS_TREE_BIGKEYS	0x00000002	/* key length is u16 instead of u8.
167 						   used by hfsplus. */
168 #define HFS_TREE_VARIDXKEYS	0x00000004	/* variable key length instead of
169 						   max key length. use din catalog
170 						   b-tree but not in extents
171 						   b-tree (hfsplus). */
172